


The Curious Case of Mycroft and Sherlock Holmes

by zadigfate



Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Backstory, Brothers, Gen, Telepathy
Language: English
Status: Completed
Published: 2012-04-22
Updated: 2012-04-22
Packaged: 2017-11-04 03:23:11
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,488
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/389183
Author URL: https://archiveofourown.org/users/zadigfate/pseuds/zadigfate
Summary: <blockquote class="userstuff">
              <p>Sometimes Mycroft read him bedtime stories completely though his thoughts. Sometimes he told Sherlock jokes to make him laugh at dinner time and said rude things about their guests that would surely make Mummy angry if she could hear them. Mycroft taught him new words and corrected his grammar when he phrased something incorrectly. They 'talked' all the time, and Sherlock's thoughts became sharper and more articulate every day.</p>
            </blockquote>





	The Curious Case of Mycroft and Sherlock Holmes

Mycroft and Sherlock Holmes sat in opposing armchairs in 221B. Neither of them said a word.

 

Sherlock plucked at the strings of his violin, occasionally looking up to fix his brother with a glare of irritation.

 

Mycroft kept his eyes focused on Sherlock, fiddling absentmindedly with the handle of his umbrella. He narrowed his gaze. Sherlock looked up and frowned, giving his violin a particularly violent pluck.

 

Mycroft rolled his eyes. Sherlock leaned backward and smirked.

 

Morning light streamed in from the broken windows that faced out towards Baker Street. The occasional siren could still be heard approaching the building across the street, even hours after the initial explosion.

 

Mycroft's head turned sharply in the direction of the door, Sherlock's following an instant later. Footsteps were climbing the seventeen steps of the front staircase and a familiar voice was calling, " _Sherlock? ...Sherlock?_ "

 

Moments later, John Watson rushed through the door of their flat, coming upon the two brothers sitting silently across from each other.

 

"John," Sherlock greeted him in a hoarse voice.

 

John was out of breath from running. "I saw it on the telly, you okay?"

 

"Me? What?" He seemed a bit out of sorts. "Oh, yes, I'm fine. Gas leak, apparently." Sherlock looked back towards Mycroft and spoke to his brother for the first time that morning: "I can't."

 

**

 

"How has little My been reacting to the new baby? Jealous?"

 

"Not at all!" Mrs Holmes laughed and raised the teacup to her lips. "He's absolutely wonderful with Sherlock; always seems to know just what he wants. When Siger and I haven't got a clue, Mycroft comes in and divines it in an instant."

 

Her friend smiled politely. "How sweet! He'll be a wonderful older brother."

 

"Yes, they've just taken to each other so quickly. Mycroft adores him, and Sherlock just seems so stimulated by his presence."

 

"Charming."

 

**

 

It crept up on them slowly. It wasn't until much later on that Mycroft would realize his relationship with his baby brother was unique. Unsurprising; he was only seven years old when Sherlock was born, and though precocious, he was young enough to still be learning what was normal in the world. As he'd had no other siblings before Sherlock came along, he had no convenient measure of what a normal relationship between brothers ought to be like.

 

So he didn't think anything was unusual about how he could read Sherlock better than even his parents. The baby would begin to cry and he could interpret it as clearly as if Sherlock was screaming the words at him: ' _Bottle!' 'Sleepy!' 'Change me!' 'Hold me!_ '

 

Sometimes it would come to him in the moments right before Sherlock started to cry. Mycroft would be sitting on the settee near Sherlock's bassinet, reading a book, when it would suddenly occur to him: Sherlock wanted another bottle. And a minute later the baby would begin to cry.

 

Mycroft didn't give it much thought. He was already a very observant child and could gather information from simply watching the children and adults that surrounded him. He could do it with strangers; of course he would have no problem deducing the needs of his own baby brother.

 

He noticed that Sherlock reacted to his presence more strongly than either of their parents'. When Mycroft was nearby, Sherlock was more active, more alert, more restless. He'd already learned not to get too close to Sherlock while he was sleeping. Even when he thought he was being quiet, Sherlock frequently woke up without provocation in his presence, much to everyone's annoyance. Mycroft got used to avoiding the sleepy Sherlock as much as possible.

 

Their parents were constantly cooing over what a good brother Mycroft was, how sensitive he was to his baby brother's needs. He wasn't quite sure why.

 

**

 

Mycroft started to think something was a bit strange when Sherlock vocalized his first word ("book" – more accurately just "buh", but close enough to count). Their parents were thrilled, but Mycroft was unsurprised. He had already heard it.

 

The first time was just a few days before. Sherlock was rolling around on the floor and chewing on the tail of a plush otter a few feet from his older brother while their mother made lunch in the other room. Mycroft sat on the floor against the front of the couch, reading a book as usual.

 

Sherlock looked in his direction and released the poor, battered otter from his jaws. He made one of his indiscriminate baby sounds and crawled over to reach for the book. Mycroft felt it again, the vague demand from Sherlock: ' _Want it_!'

 

"You want to see my book?" he offered, lying it flat on his lap so that Sherlock could see.

 

Sherlock placed one of his little hands over the text, seeing no pictures. Confusion.

 

"It's a book, Sherlock," said Mycroft. Their parents had lately been trying to teach words to Sherlock, repeating them over and over to him while he looked on blankly. Mycroft used one of his hands to gesture to the pages in front of them. "A _book_. This is a _book_."

 

Sherlock was facing away from him. In the same baby voice that he heard Sherlock babble in all day, he heard an unsteady: ' _Bbb-uhhk_?'

 

"Yeah, Sherly," said Mycroft out loud. "It's a _book_."

 

Sherlock considered the object in front of him, looking up at Mycroft for confirmation. ' _Bbbuuuhk_.' Mycroft swore he could hear it, but it was probably his imagination. At eight years old, Mycroft barely gave it a thought.

 

Over the next couple of days, it was like Mycroft could hear the wheels turning in Sherlock's little head. He was lying on the floor, playing again with the unfortunate otter, and caught a glimpse of one of their father's books on the table. He gave the object his absolute attention. ' _Bb—uuhk_ '?

 

"It's a book," said Mycroft out loud from the other side of the room. He was reading one himself and hadn't looked up from the pages.

 

On another occasion, Mycroft was reading Sherlock a bedtime story – Sherlock lying in his crib and Mycroft sitting cross-legged on the floor with his back against the bars, so Sherlock could see the pictures if he liked. He had just started reading when he heard Sherlock say it again: _'Buuhk'_?

 

"That's good, Sherlock," said Mycroft. "It _is_ a book."

 

So when Sherlock pointed at a book in their mother's hands one afternoon and vocalized "Buhh!", Mycroft was surprised at the strength of their parents reaction.

 

"He's been saying it for a few days now," said Mycroft, completely unimpressed. "And he's said it better, too."

 

He was chastised for not having told them earlier. Sherlock, overjoyed with the reaction he'd provoked in his parents, chirped happily: "Buhh! Buhh! Buhhh!"

 

**

 

As Sherlock's vocabulary grew – rapidly, of course – and his thoughts became more organized and articulate, he and Mycroft began to have more elaborate unspoken exchanges. It was around this point, when Sherlock became able to express his thoughts and desires with words, that Mycroft fully realized how strange their relationship really was.

 

It was impossible to deny now that he was actually hearing Sherlock's thoughts. What had before been vague notions from Sherlock became articulated demands. Rather than feeling a general impression of what Sherlock wanted, Mycroft could hear the words as clearly as if they'd been spoken out loud: ' _Feed me!_ ', for instance, had been replaced with, ' _I am hungry, I want a sandwich_.'

 

Mycroft was also old enough by then to know that reading his little brother's thoughts was not normal, and he was wise enough to know that he shouldn't tell anyone about their odd connection. He impressed this upon Sherlock as soon as he came to the conclusion himself, and although Sherlock was still too little to properly understand, Mycroft warned him all the same: ' _Don't tell_. _Don't tell any body that we talk like this, ever._ '

 

Their parents alternated between praising Sherlock for his rapidly growing vocabulary and advanced command of the language and expressing disappointment that he was always so quiet. There was rarely any reason for him to talk; he had long, complicated conversations with his brother all the time, and he had no desire to talk to anyone else. If he needed something, he could always ask Mycroft. He had no need for all the tedious mouth-flapping that came with physical speech. Not when there was Mycroft.

 

As soon as their bond became clear to him, Mycroft began devising experiments to test his connection with Sherlock. It was frustrating to work with a two-year-old, but at least Sherlock was bright enough to understand his instructions most of the time. They tried sending each other things like pictures and colours and feelings, but it seemed like words and generalized notions – unarticulated bursts of thought – were the only things they could receive from each other. In other ways, it was exactly like normal hearing. It had about the same range, and the volume could be altered. It was difficult to hear each other through physical barriers like walls.

 

Sometimes Mycroft read him bedtime stories completely though his thoughts. Sometimes he told Sherlock jokes to make him laugh at dinner time and said rude things about their guests that would surely make Mummy angry if she could hear them. Mycroft taught him new words and corrected his grammar when he phrased something incorrectly. They 'talked' all the time, and Sherlock's thoughts became sharper and more articulate every day.

 

**

 

Sherlock started primary school with a speech disability. It was a consequence of speaking so rarely that his mouth had not developed very well to form words at the appropriate age. His parents had put him in speech therapy from about four years of age, but he still started primary school with the inability to enunciate clearly.

 

Sherlock _hated_ school.

 

In his head he spoke so fluidly, so intelligently. The words formed flawlessly in his mind, but when he opened his mouth to express them, they came out with the articulation of a toddler. The other kids laughed at him. He knew that he sounded _stupid_ when he opened his mouth and he _hated_ it.

 

He was miserable and started talking even less. He didn't speak to his classmates at all.

 

**

 

It was probably for the best that Mycroft went off to boarding school, to Harrow, at the same time that Sherlock went into primary school. The brothers were devastated to be apart, but Sherlock eventually did start speaking to the other people around him. Once it struck him that speech would be unavoidable in the future, that Mycroft would not always be there, he devoted himself to improving his speech. He sat alone in his bedroom going over the pronunciation exercises his speech therapist gave him until he could enunciate them perfectly.

 

Mycroft wrote to Sherlock frequently, but it just wasn't the same.

 

**

 

Fifteen-year-old Mycroft and eight-year-old Sherlock sat in the gardens of their parents' home during the summer holidays, just a few feet apart. Neither were looking at the other, but they were communicating. More specifically, they were experimenting.

 

Now that Sherlock was older and smarter, it had opened up a new range of mental experiments that were previously impossible to attempt with his immature mind. Sherlock had been coming up with some experiments of his own, and was eager to try them out with Mycroft. It was hard to find the time and privacy - they couldn't just sit next to each other quietly for hours, too suspicious – but thankfully their parents were used to their solitary tendencies and usually let them play alone, uninterrupted.

 

They were experimenting with non-verbal thoughts, which had always been a challenge in the past. It was possible to send each other general impressions – Sherlock had been doing it through his infancy before he had developed the capacity for language – but the interpretations by the other person didn't always come out right. Sherlock thought, and Mycroft agreed, that if they could master non-verbal thoughts, it would be much more efficient than communicating with words.

 

Sherlock had one of his mother's coffee table art books in his hands, and he was staring intensely at a cubist painting. It was impossible to send mental images to each other, so they experimented with sending each other a general notion of the artwork. It was much harder than Sherlock had anticipated, trying to convey the general impression to Mycroft without accidentally slipping in words like "blue" or "fish".

 

_'Thick lines, strong colours,'_ Mycroft thought. ' _Modern art?_ '

 

' _Yes.'_

 

_'No human subjects, a still scene.'_

 

_'Yes.'_

 

_'It's... blue. Painted almost entirely with cool colours. There's water in it.'_

 

_'Yes.'_

 

_'But something sticks out. There's something that doesn't match the pattern. A different colour, very bright and different. Something red or orange?'_

 

_'Yes.'_

 

_'Expressionism?'_

 

_'No.'_

 

They were silent for a moment – mentally and physically.

 

' _The artist,_ ' Mycroft thought. ' _Is he French?_ '

 

' _Yes. You got that?_ '

 

' _It feels sort of... French-y_.'

 

Sherlock felt a thrill of excitement. They were getting somewhere. ' _Can you guess?_ '

 

' _It's not Picasso, is it? It feels sort of Picasso-like._ '

 

' _Close. Matisse_.'

 

' _Ah, bugger_.'

 

**

 

' _Sherlock? Please, talk to me._ '

 

Even though Sherlock was sitting right in front of him, there was nothing from his end. He looked away determinedly. Not so much as a general sense of ' _go away_ ' slipped through from his mind.

 

Mycroft frowned. ' _I know you can hear me._ '

 

' _Piss off, My. I've got enough in my head without your voice buzzing around in it._ '

 

' _You haven't talked to me once since I got home from uni._ '

 

' _I've talked to you plenty.'_

 

_'Right, and since when did you ever talk to me out loud?'_

 

_'I've got enough of my own thoughts to occupy me, all right? I don't need yours crowding the place up.'_

 

Mycroft sighed. Sherlock picked up his violin and began to play with angry strokes of his bow. The two brothers sat across from each other, and for once they were completely silent.

 

**

 

Mycroft stood outside Sherlock's flat on Montague Street, tapping the sidewalk impatiently with his umbrella. He didn't have time for this. He was a very busy man on the rise in the civil service and there were plenty of other things that ought to be commanding his attention. But no one had heard from Sherlock in a few days, and Mycroft had gone looking for him to ease his conscience. It was just like the bastard to not be at home when he came around to call.

 

Mycroft was just contemplating the possibility of leaving him a voicemail and going back to work when he felt something fuzzy and tangled at the edge of his thoughts, like radio static. He could quite easily distinguish between his own thoughts and Sherlock's now and knew that this one was Sherlock-generated. He usually kept his 'vocal' mind so quiet in Mycroft's presence – perhaps he didn't realize he was thinking 'out loud', as it were.

 

Sherlock came into sight from around the corner, looking much worse than the last time Mycroft had seen him. He was thinner, gaunt even, with dark shadows under his eyes. His hair was a mess, his face unshaven, and he clearly hadn't changed his clothes in a few days. Mycroft's heart clenched – perhaps he ought to have paid a visit sooner. He sent Sherlock a sort of mental ping in greeting.

 

Sherlock's head snapped up, though it seemed to take his eyes a moment to focus on Mycroft. When they did, they narrowed dangerously. They were tinged with pink.

 

' _Piss off,_ ' he growled. But there was something so off and so _not-_ Sherlock about his thought this time. It was wide, and loopy, and the words themselves seemed _high_. They were barely distinguishable against the crackling background of static that was louder now that Sherlock was closer.

 

Mycroft didn't need to read his thoughts to deduce the signs of heavy drug use.

 

' _What have you gotten yourself into, Sherlock?_ ' he thought sadly.

 

' _Go away, My. I don't need you to be my keeper_.' More of those loopy words.

 

' _This is unacceptable, Sherlock_ ,' he frowned. ' _We need to get you help_.'

 

Sherlock replied with something that was lost to the static.

 

' _I can't hear you over that noise_ ,' thought Mycroft worriedly. ' _What is it?_ '

 

' _I can't turn it off_ ,' thought Sherlock grimly, loud enough to rise over the background hum. ' _I don't know what to do. I can't turn it off, I can only turn it down... temporarily_.'

 

Mycroft realized then that it wasn't static at all – the fuzziness in the background was thoughts. Dozens of different trains of thought, running at different paces, overlapping and forming connections and making deductions and then deductions based on deductions and so on, completely unbidden until they were an unintelligible tangle. His own mind could be a mess of thought sometimes, but never this badly.

 

He conveyed mentally, with one of their general notions, that he understood. ' _Sherlock,_ ' he thought, ' _We can find some way to help you. There must be another way_.'

 

' _Great, let me know when you find it,_ ' he hissed back. ' _In the meantime, I'm going to have a shower and take a nap. Good luck with that_.'

 

Sherlock moved for the front door, pulling out his key.

 

Mycroft lifted an arm to stop him. ' _Sherlock--_ '

 

He spun around and faced Mycroft with wide, angry eyes. ' _PISS OFF!_ ' For just an instant, the background hum of his thoughts grew so loud that Mycroft winced and backed away. Then Sherlock was inside and slamming the door, leaving his brother standing on the front steps.

 

Mycroft pulled a cell phone out of his pocket and started to dial. He might occupy only a minor position in the British government at this point, but he did already have some powerful connections.

 

**

 

Mycroft caught Sherlock and this John Watson fellow just as they were leaving together from the crime scene at the college. It was John that saw him first, nudging Sherlock to alert him to his presence. Sherlock saw him and immediately rolled his eyes.

 

' _Really, Mycroft?_ '

 

Mycroft smiled. "So, another case cracked. How very public-spirited of you. But that's never really your motivation, is it?"

 

Their spoken conversation was merely for the doctor's benefit. After a lifetime of practice, the brothers were masters at holding two conversations at once: the spoken one, to hold up appearances, and the more honest one between their minds.

 

' _What do you want with John? He already refused your offer.'_

 

' _You're looking much better, Sherlock._ '

 

' _You wouldn't come to all the trouble of making your way down to a crime scene just to tell me that, what do you want?_ '

 

' _When I heard you intended to actually live with another person, I was concerned. But from what I've heard of the situation on the way over here, perhaps I shouldn't be._ ' He sent Sherlock a general impression of his deduction, something they did often, containing little glimpses of information: the dead killer, powder burns on the doctor's fingers, his military background, a shot made across a long distance from a handgun, the steadiness of his hands. A chain of evidence bundled into a thought that took a mere second to process.

 

There was a tone of smugness in Sherlock's reply. ' _And?_ '

 

' _I haven't quite decided whether this man will be your making or your undoing_.'

 

' _I doubt I'll be losing sleep over your dilemma_ ,' he thought icily. ' _If that's all, we'll be going. I haven't eaten since I got on the case and I'm absolutely starving_.'

 

' _Be careful, little brother._ '

 

' _Piss off, My_.'

 

Sherlock huffed and stalked off. Doctor Watson stayed for a moment to exchange a few words with Mycroft and his secretary before running after him. Mycroft watched them for a moment, genuinely unsure what to think. This would require some looking into.

 

**

 

Sherlock swung the bow of his violin at Mycroft as he stood up. ' _I have no interest in your case_ ,' he thought threateningly, ' _And I don't appreciate you coming here to enquire after my personal life._ '

 

' _Enquire? Dear brother, you know I never need to enquire,'_ he smirked. ' _A look around your flat is all it takes._ ' He sent Sherlock another deduction balled up in a notion: the communal desk, their belongings blended together, evidence of shared meals.

 

Sherlock narrowed his eyes.

 

' _I only want to make sure that you're happy,_ ' thought Mycroft. ' _And I really do want you to look into this case._ '

 

' _Give it to John_ ,' Sherlock thought dismissively.

 

' _If you insist,_ ' sighed Mycroft.

 

' _And stop watching us. Get your cameras out of here. I mean it._ '

 

' _If I must_.'

 

Mycroft turned around. He'd lingered too long; John was already looking between the two of them with confusion. He smiled and held out the case file to John, who looked surprised at the offering. The moment was already forgotten.

 

He wondered if Sherlock would ever tell John.


End file.
